I hope there is someone at the initial rally-point for the marchers who can scan the area for tour buses. You know these folks didn’t just show up on their own. Find the buses that brought them in. Then find the owners and see who paid for those buses. Follow the money.
Soros, anyone? Anyone? Buehler?
Exactly. I would add that if you want to stop the Antifa communists from starting trouble you don’t let them off their buses.
Creative and non-violent action to stop this in its tracks, would be to go let all the air out of the tires of the tour buses.